Compounds of the cyclopentanopolyhydrophenanthrene series and process ofmaking same



Patented Dec. 30, 1952 POLYHYDROPHEN AND PROCESS1OF Karl Miescher, Riehen,

Basel, ceutical Products,

rial No. 126,054. 1948 This invention relates to the preparation of compounds of the cyclopentanopolyhydrophenanthrene series by reduction of'redu'cible substituents of compounds of the said series with lithium-aluminum hydride, in which process a 3- ositioned a:;8-uns aturated keto-grouping present is not hydrogenated.-

A'further object of this mventionis the preparation of new compounds of the cyclopentanopolyhydrophenanthrene series, such as, for ex ample A -3-keto-22-hydroxy-bisnor cholenes.

According to the present invention inc-unsaturated 3-ketones of the cyclopentanopolyhydrophenanthrene series are temporarily converted into their enol ethers or cyclic acetals for protection of the 3qpositioned keto group and treated, for thepurpiose of reduction of reducible substituents, with lithium-aluminum hydride.

The (rm-unsaturated ketones of the cyclowhich pentanopolyhydrophemanthrene senies, contain as reducible substituents for example, a keto, aldehyde, free or esterified'carboxyl, an acid chloride, acid anhydride, acid amide or nitro group, may be converted into any convenient enol ether or cyclic acetal. Suitable enol ethers: are those of the aliphatic, alicyclic or ar aliphatic series; in partioular alkyl ethers are employed, as for example, methyl, ethyl or propyl ethers. There may be particularly mentioned the enol ethers of A -3-leto;bisnor-cholenic acidand its acid derivatives, primarily their esters, suchias the methyl ester, and also the 3-enol ethers of A -3:1'7-androstend ione. In the manufacture of the cyclic aicetals of these particularly of the ethylene glycol, there are used the 1,2-dio1s or the correspondiug-alkylene oxides in the presence ofan acid catalyst. ,g

The reduction is advantageously carried out in the presence of an indifferent solvent in which the lithium-aluminum hydride is soluble, in partlcular in the presence of ether, or also of tetrahydrofurane, butyl ether or benzene or of mixtures of such diluents, such as in the presence of a mixture of ether and benzene.

The-enol ethers or cyclic acetals of hydnoxyketonesor amino-ketones obtained in the course of this process can be hydrolyzed in the customary manner in order to produce the corresponding ketones.

The ketones obtained are in part known and in part constitute new compounds. Some of them merit application as therapeutic media. The ketones may also be employed as intermediate products for the manufacture of therapeutically valuable compounds.

starting materials,

2 Claims. (Cl. 260-3974) AN THRENE SERIES MAKING SAME and Charles Meystre,

Switzerland, assignors to Ciba Pharma- Inc., Summit, N.

No Drawing. I Application November 7, 1949, Se-

In Switzerland November 17,

The following examples illustrate the invention, the parts being by weight unless otherwise stated and the relationship between parts by weight and partsby volume being the same as that between the kilogram and liter:

Example 1 10 parts of the ethyl enol ether of the methyl ester of M-B-keto-bisnor-cholenic-acid aredissolved in 200 parts by volume of dry ether and slowly added, with exclusion of moisture, to a well stirred mixture of 2.5 parts of lithiumaluminum hydride in 200 parts by volume of dry ether. Thereupon the solution produced is further stirred for 15 minutes and then first carefully treated with parts by volume of water and 1'70 parts by volume of 10 per cent. sulfuric acid. The ethereal solution is then washed with water, dried and evaporated. The crude enol ether of A -3-keto-22hydroxy-bisnorcholene thus obtained, when recrystallized from ethanol, melts unsharply at 125-144 C.

are obtained.

For the manufacture of the enol ether Ternn e 1t v ed t 9 ester of A -SB-hydroxy-bisnor-cholenic acid is first oxidized according to Oppenauer with cyclohexanone in the presence of aluminum isopropylate in toluene. The methyl ester of A -3-keto-bisnor-cholenio acid thus obtained, which when recrystallized from acetone melts at l83-184= C., is then converted in the customary manner with orthoformic acid ethyl ester in acidified ethanol solution into the corresponding ethyl enol ether, which when recrystallized from methanol melts at 103-106" C.

Example 2 2 parts of the 3-ethyl enol ether of A -3:17- androstendi'one are dissolved in 200 parts by volume of dry ether and slowly added, with exclusion of moisture, to a well stirred mixture of 0.5 part of lithium-aluminum hydride in parts for example, the methyl by volume of dry ether. The solution produced is further stirred for 15 minutes and thereupon carefully treated, with 20 parts by volume of water and 40 :parts by volume of 10 per cent. sulfuric acid. The ethereal solution is then washed with water, dried and evaporated. The crude enol ether of A -3ketol7-hydroxy-androstene is, without further purification, dissolved in 100 parts by volume of alcohol and the solution treated with 10 parts by volume of ZN-hydrochloric acid and allowed to stand for 24 hours. The solution is thereupon evaporated in vacuum and in this manner the crude A -3-keto-17-hydroxyandrostene (testosterone) obtained, which can be purified in the customary manner. For example, from diluted acetone, needles are obtained of melting point 152-153 C. ([a]D =+l09 in ethanol).

Example 3 .10 parts of the 3-.ethyl enol ether of A pregnene-17fiol-3-one-21-acid methyl ester are dissolved in 250 parts by volume of dry ether and slowly added, with exclusion of moisture, to a well stirred mixture f 2.5 parts of lithium-aluminum hydride in 200 parts by volume of dry ether. The solution produced is further stirred for 15-20 minutes and-thereupon carefully treated with 100 parts by volume .of water and 17 0, parts by volume of sulfuric :acid of 10 per cent. strength. The ethereal solutionis then washed with water, dried and evaporated. The crude ethyl enol ether of A -pregnene-1-7p,21-diol-3-one thus obtained is dissolved in 250 parts by volume of methanol and the solution treated with parts by volume of ZN-aqueous hydrochloric acid and allowed to stand at room temperature for 1 2 days. The solution is thereupon evaporated in vacuum and taken up in chloroform. The chloroform solu tion is washed with water, .dried and evaporated. Upon recrystallization from a mixture of isopropylether hexane, the residue produces A pregnene-17;9,21-diol-3-one of melting point 243-246 C.

The ethyl enol ether of M-pregnene-l'Zfl-ol-3- one-21-acid methyl'ester, used as starting material, is obtained from A -androstene-3,17-dione- 3-.ethyl enol ether by condensation with bromo acetic acid ester and zincsaccording tothe method of Reformatzky.

Example 4 A solution-of 2"p'arts of theB-ethy'l enol ether of A -pregn'adiene-3-one 2l acid-methyl ester in 200 parts -by volume of dry tetrahydro'furane is added, with exclusion of moisture, to a well stirred mixture of 2.5 parts of lithium-aluminum hydride and. 200*:pa'rts by volume of dry tetrahydrofurane. Stirring is "continued for another '1'0-20minutes hydrochloric acid and whereupon 20 parts by volume of water, then 180 parts by volume of sulfuric acid of 10 per cent. strength and finally ether are added gradually.

The ethereal solution is then washed'with water,

dried and evaporated. The crude ethyl enol ether of A -pregnadiene-21-ol-3-one obtained is dissolved in 200.parts by volume of ethanol and the solution-treated with 20 parts by volume of 2N- allowed to stand at room temperature for vv1-2 days. upon evaporated in vacuum and the crude A pregnadiene-21-ol-3-one obtained purified in the customary manner. Upon crystallization from acetone-methanol it melts at -137 C.

The starting material in the above example, namely the 3-ethyl enol ether of A -pregnadiene-3-one-2l-acid-methyl ester, is obtained from the 3-enol ether of A -androstene-3,17-dione by condensation with bromo acetic acid ester and zinc according to the method of Reformatzky,and

KARL MLESCHER. CHARLES MEYSTRE.

REFERENCES CITED The following references are of record in the file of this :patent:

UNITED STATES PATENTS Number Name "Date 2,166,877 Re-ichstein July 18,1939 2,183,589 Reichs"teitl 'Dec. 19, 193.9 2,294,433 WBStbhal Sept. 1, 1942 2,324,522 Loge'mann July 20, 1943 2,356,154 Fernholz Aug. 22, 1944 2,462,133

The solution is there- 

1. PROCESS FOR THE REDUCTION OF COMPOUNDS OF THE CYCLOPENTANOPOLYHYDROPHENATHRENE SERIES, WHICH COMPRISES TREATING A MEMBER OF THE GROUP CONSISTING OF $4-3-KETO-BISNOR-CHLOENIC ACID AND $4-3-KETO-BISNOR-CHOLENIC ACID DERIVATIVES IN THE FORM OF A MEMBER OF THE GROUP CONSISTING OF 3ENOL-ETHERS AND 3-CYCLIC ACETALS WITH LITHIUMALUMINUM HYDRIDE AND HYDROLYZING THE SO FORMED REACTION PRODUCT, WHEREBY $4-3-KETO-22-HYDROXYBISNOR-CHOLENE IS OBTAINED. 